The present invention relates to a package of the type having a container body consisting of four side walls, opposite each other in pairs, and a bottom and a top end wall. More specifically, the present invention relates to a package in which the top end wall is joined along each of two opposite lateral edges to two triangular, double-walled lugs, and a sealing fin projecting from the end wall, wherein two material layers are joined to one another inside-to-inside, extends over the top end wall as well as over the top sides of the triangular lugs up to their points.
It is known in the technology of packaging that packages can be manufactured by starting out from a weblike packing material which is folded up to a tube. The longitudinal edges of the web are joined together in a sealing joint, and the tube formed is filled with the intended contents, e.g. milk, fruit juice or othr fluid or semifluid products. Thereafter the tube filled with contents is sealed off by repeated transverse seals along narrow flattening zones situated at a distance from one another at right anlges to the tube axis so as to form sealed tube sections filled with contents. The tubes are then form-processed by folding to parallelepipedic packages which are separated from the tube by means of cuts in the sealing zones. Packages of the type mentioned here have double-walled, triangular lugs along four of the corner edges of the packages and a standup sealing fin alongside the top and bottom end surfaces of the packages. Moreover, these sealing fins extend over the triangular lugs up to their points.
The packages of the type specified here are used very generally for packaging in the distribution of, for example, milk and fruit juices. The packages are usually opened with one of the triangular lugs, which are folded down and sealed to the side wall of the package, being raised up and cut off so that an emptying channel is formed which communicates with the inside of the package.
It has proved advantageous in certain cases to place an opening cut in the sealing fin for opening the sealing fin within the desired opening region, which includes the part of the fin extending over one of the triangular lugs and over a part of the adjoining top end wall of the package. The sealing fin is opened by breaking up the sealing bond between the sealed layers in the sealing fin, through the insertion of a tear-wire or a tear-strip in the sealing fin. Another method of providing an opening in the sealing fin includes arranging the actual seal of the sealing fin at its free outer edge and providing below the seal but above the base line of the fin a cut or tear perforation alongside the fin.
In forming an emptying channel through which the contents of the package can be poured out in a convenient manner, it is not enough, however, just to create an opening in the fin either by tearing up the sealing bond of the fin or by cutting or ripping open a longitudinal cut through the fin. The slotlike opening has to be widened to form a pouring channel with a greater passage area. It is known that such a larger emptying channel can be formed by raising up and pushing back the opened lug so as to produce a rhomboid opening. However, it has also been found that the formation of such an opening is rendered considerably more difficult if the sealing fin or parts of the sealing fin form the opening edge of the emptying channel. The reason for this is that the sealing fin normally is inclined or folded down towards the top end wall of the package and to a certain extent is even locked in this inclined or folded down position owing to the triangular lug, which is positioned opposite the lug used as an emptying opening, being folded in against the side wall of the package. This means that the sealing fin is forced to rest against the top end wall of the package at least along parts of the end wall. This tendency of the sealing fin to slope against the top side wall of the package has the result that the formation of the rhomboid emptying opening is made difficult. Instead of a rhomboid opening, frequently an angular, practically slotlike opening is obtained, since the one side of the triangular lug fails to "fold out" in the intended manner, but instead is folded-in in the opposite direction. This is generally referred to as a "collapsed lug".
The reason for these collapsed lugs is that the sealing fin or parts of the sealing fin form a relatively rigid "frame". The parts of the sealing fin which slope towards the top end wall do not have any natural tendency to fold outwards but instead, because of the stresses which arise in the "frame", more readily fold inwards to produce the above-mentioned result.
The package according to the pesent invention eliminates the disadvantages associated with the prior art. According to the present invention, a package is provided having a container body formed from a packing material. The package includes four side walls located opposite each other in pairs, a bottom end wall and a top end wall which is joined along each of two opposite lateral edges to two, triangular, double-walled lugs. A sealing fin extends over the top end wall and top sides of the triangular lugs to a point of each lug. The sealing fin, which is formed by joining inside layers of the packing material, is folded down along at least a portion of its length against the top end wall and is retained in its folded down position. A region of the sealing fin is adapted to be torn open in order to form an emptying channel in the package. At least one cut is provided in the sealing fin for weakening the packing material in order to inhibit collapse of the lugs when the package is opened.